Botrychium Monitoring and Information Gaps Interagency Special Status Species Program Final Report April 2012 Botrychium ascendens, Guard Station Meadow, photo by Kirk Larson Kathy Ahlenslager and Amy Cabral Colville National Forest, 765 S. Main, Colville, Washington 509-684-7178, [email protected] 509-684-7175, [email protected] Contents Introduction ..................................................................................................................................... 1 Background ..................................................................................................................................... 4 Methods........................................................................................................................................... 5 Results ............................................................................................................................................. 8 References ..................................................................................................................................... 29 Acknowledgements ....................................................................................................................... 30 Appendix 1. Locations of 12 Monitoring Sites on the Colville National Forest. ........................ 31 Appendix 2. Botrychium Monitoring Plot Size Summary ........................................................... 32 Appendix 3. Landform Groups and Land Type Associations. .................................................... 41 Appendix 4. Key to Landforms and Land Types (Davis 1998) on Appendix 2. ......................... 42 Appendix 5. Weather, Aerial Photo Comparisons, Soils and Drainage by Site. ......................... 44 Appendix 6. Comparison of Aerial Photos. ................................................................................. 47 Appendix 7. Associated Species. ................................................................................................. 60 Appendix 8. Population Counts with Annual Precipitation. ........................................................ 66 Appendix 9. Dates Plots Read. .................................................................................................... 74 Appendix 10. Population Counts with Moving Averages. .......................................................... 75 Appendix 11. Two-tailed Paired t-Tests. ..................................................................................... 88 Introduction The objective of the project is to determine population trends of six Sensitive Botrychium species (Table 1) (USDA FS 2011) at 12 sites (Appendix 1) on the Colville National Forest. In the summers of 2010 and 2011, 11 permanent monitoring plots and 12 permanent monitoring transects were read at a total of 12 sites. Table 1. Rarity Rankings of Taxa. The key to rankings is below the table. Taxa Global Rank Federal Status WA State WA State Rank Status Ascending moonwort G2G33 SC S2 S (Botrychium ascendens) Crenulate moonwort G3 SC S3 S (Botrychium crenulatum) Western moonwort G3G4 S1 T (Botrychium hesperium) Skinny moonwort G2? S1 T (Botrychium lineare) Two-spiked moonwort G2 SC S2 T (Botrychium paradoxum) Stalked moonwort G2G3 SC S2 S (Botrychium pedunculosum) Global Rank G2 = Imperiled globally (6 to 20 occurrences). G3 = Either very rare and local throughout its range, or found locally in a restricted range (21 to 100 occurrences). G4 = Apparently secure globally. USFWS Federal Status SC = Species of Concern. An unofficial status, the species appears to be in jeopardy, but insufficient information to support listing. Washington State Rank S1 = Critically imperiled (5 or fewer occurrences). S2 = Imperiled (6 to 20 occurrences), very vulnerable to extirpation. S3 = Rare or uncommon (21 to 100 occurrences). Washington State Status S = Sensitive. Vulnerable or declining and could become Endangered or Threatened in the state. T = Threatened. Likely to become Endangered in Washington. Although Botrychium ascendens was included in the proposal for this project, there were not enough plants found to include it. On the Colville National Forest B. ascendens is documented from Guard Station Meadow, where 48 plants were discovered in 1995 near a cattle trough. Plants were caged with a wire cattle exclosure. In 2002 19 plants were seen and 3 in 2003. None have been seen since. Guard Station Meadow is a large 87-acre meadow that has been treated with herbicides for meadow hawkweed. All other proposed work was completed and is described in Table 2. 1 Table 2. Proposed Botrychium Monitoring Work and Status. Proposed Work Status 1 Read 25 permanently marked transects at 12 locations, 11 permanent monitoring plots including six Sensitive species and 12 permanent monitoring transects were read at a total of 12 sites. 2 Analyze data using paired t-tests for all sites listed to See Results #5. assess population trends. 3 Assemble a description of habitat in terms of soil type See Results #4. and when past disturbances (fire, timber harvest, and grazing histories and intensities) occurred 4 Compare plant counts with the previous year's weather See Results #3. (e.g., dry winter/wet spring) to evaluate possible patterns. 5 Complete sighting and survey forms for all Sensitive Completed (USDA FS 2012f). taxa, resulting from FY10 and FY11 monitoring. Record data on the sensitive plant GIS layer and in the NRIS database. 6 Compile all of the above for each site into a report. Completed. Figure 1. Botrychium ascendens, Guard Station Meadow, photo by Kirk Larson. 2 Figure 2. Botrychium crenulatum Figure 3. Botrychium hesperium Colville National Forest Paradise Meadow Photo by Botany Crew. Photo by Botany Crew 6/30/2009. Figure 4. Botrychium lineare Figure 5. Botrychium paradoxum Bailey Creek Bestrom Meadow Photo by Botany Crew 7/3/2007. Photo by Botany Crew 7/12/2010. 3 Background In the 2007 Region 6 “Conservation Assessment for 13 Species of Moonworts (Botrychium Swartz Subgenus Botrychium),” Dr. Cindy Johnson-Groh summarized: “…the impact of disturbance on Botrychium is poorly understood. Some species of Botrychium clearly prefer old disturbance sites, whereas others do not. Sites, which were disturbed approximately ten years ago, seem ideal habitat for many species of Botrychium. Roadside ditches, campgrounds, ski hill runs, avalanche chutes, and railroad right-of-ways are common habitat for moonworts. Seemingly suitable sites that have been disturbed more recently or longer ago often do not support moonworts or support smaller populations. …..Historic disturbance appears to be an important factor for moonwort establishment. Nothing is known about the mechanisms of this behavior and little is known about the impact of recent disturbances on extant populations.” This project contributes towards answering several questions concerning the management of moonworts, which were identified in the 2007 Region 6 “Conservation Assessment for 13 Species of Moonworts (Botrychium Swartz Subgenus Botrychium) (2007):” What specific site characteristics are necessary to maintain existing occurrences? What microclimate/microsite conditions favor survival, growth, and reproduction of moonworts? How can we identify high likelihood habitats for these species in order to prioritize inventory efforts or to ensure habitat conservation? Is there a correlation between the previous year's weather (e.g., dry winter/wet spring) and high or low population counts during the summer? What level of disturbance (overstory removal, grazing, fire, etc.) do these species tolerate? o Some sites are flat benches associated with old river or stream terraces where soils are alluvial in origin. Are periodic floods part of the natural disturbance regime at these sites and, if so, what effect does this disturbance have on Botrychium? o How do populations vary in livestock grazed and ungrazed sites? How is this affecting Botrychium microsites? How much grazing is too much/enough? o What is the fire ecology of Botrychium? Also addressed in this project are several information gaps described in the 2007 R6 Botrychium Assessment: Population trends. Effective management areas (sizes) and habitat characteristics necessary to maintain known occurrences in project areas. Short-term and long-term effects of timber harvest, grazing, recreation, fire, fire suppression, and exotic plants on the maintenance of known occurrences. Identification of high likelihood habitat, to help prioritize surveys and ensure appropriate habitat conservation. The monitoring sites on the Colville National Forest were chosen for the presence of Sensitive taxa and ongoing disturbances, i.e., spring stream scouring, cattle grazing, and/or gopher activity. 4 They are on Three Rivers and Sullivan Lake Ranger Districts on the Colville National Forest and include seven cattle allotments. Since so little is known about Botrychiums, 12 permanent transects at six locations (five in western red-cedar forests and one in a grazed homestead meadow) were established on the Colville National Forest in 1995 by contractor Peter Lesica. His 1995 report, “Monitoring Botrychium crenulatum and B. pedunculosum on Colville National Forest” described transect designs, locations, and data analysis methods used for monitoring trends in plant density. The proposed data analysis for these transects would test the hypothesis that there is no change occurring in the density of plants over time. The simplest way to test this hypothesis was to compare microplot